This invention relates to improvements in or relating to fluid flow control and is more particularly concerned with a dual control assembly, for example for a shower fitting or other water outlet, where the temperature of water can be controlled by a thermostatic valve and the water flow by a flow rate valve.
Where dual controls have been provided in, for example, shower fittings, the temperature of the water may be controlled by means of a thermostatic valve governing the mix of hot and cold water flowing into the mixing chamber and the rate at which mixed water flows out of the mixing chamber through the shower head may be independently controlled by means of a flow rate valve. A disadvantage of such controls is that if a fault develops in the thermostatic valve, repair and/or service costs resulting from the need to dismantle or remove the shower body often have to be paid by the end user. In order to overcome this disadvantage with most traditional showers, it is known to provide the thermostatic valve as a cartridge or unit that can be inserted into the mixing chamber and reasonably easily extracted therefrom for instant repair and servicing or replacement, without it being necessary to dismantle or remove the shower body at all. Such cartridges/units are readily available. When such a cartridge is incorporated into a water outlet, it is known for the cartridge to be introduced into a mixing chamber from one end of the water outlet fitting, with an appropriate temperature control knob being provided at that end, and a separate flow rate valve (in the form of a ceramic disc (xe2x80x9cCDxe2x80x9d) valve) being incorporated at the other end of the fitting with an appropriate independently operable control knob at that end for controlling the flow rate. Such a design is employed on the European Continent but is not generally suitable for the United Kingdom or the United States of America owing to the orientation usually accepted or required, where the thermostatic valve control knob projects forwardly and horizontally from the wall (rater than parallel therewith) and is rotatable about an axis extending at right angles thereto. In such a design, a flow control knob positioned in line with the thermostatic valve control knob at an opposite end of the fitting would have the flow control knob facing the wall and thus could not be accessed properly.
It is known, however, to provide dual control assemblies for showers meeting British design requirements where the thermostatic valve is in the form of a cartridge or unit insertable in a mixing chamber which projects forwardly and horizontally from a wall on which the fitting is mounted. However, in order for the flow rate to be controlled a separate independently operable control knob is mounted above the thermostatic control knob and above the mixing chamber in order to control a separate flow rate valve. It is believed that such a design is disadvantageous in certain respects. For example, it is believed that said design is not as aesthetically pleasing as a design in which the thermostatic control knob and flow rate control knob are mounted in line with one another or concentrically and, preferably, operable from the same end of the mixing chamber as may be provided for where the thermostatic valve is not in the form of an insertable/extractable replacement unit or cartridge. Additionally, such a design may be disadvantageous from a cost or manufacturing point of view. In any event, it is believed that a design of dual control assembly has not been optimised more particularly for the British or American Market which includes a thermostatic valve in the form of an insertable/extractable cartridge or unit.
It is an object of the present invention to at least alleviate one or more of the aforementioned disadvantages with dual control assemblies and/or to provide a dual control assembly which is improved in at least some respect.
According to the present invention there is provided a dual control assembly comprising a thermostatic valve in the form of cartridge or unit insertable in a mixing chamber of, for example, a shower fitting or other water outlet, said assembly having an operative link or coupling between the thermostatic valve and a flow rate valve.
In one embodiment of the present invention, the operative link or coupling between the thermostatic valve and the flow rate valve is provided by a sleeve surrounding the thermostatic valve which sleeve is operatively connected to the flow rate valve. The flow rate valve is, preferably, co-axially aligned with the thermostatic valve with said sleeve being arranged to turn the body of the flow rate valve relative to an operating stem of said valve, which stem is held still relative to a mixing chamber of the shower fitting or water outlet. The sleeve (or other operative link or coupling) may or may not be part of the cartridge or unit and may or may not be arranged to rotate with the thermostatic valve to operate the flow rate valve.
Preferably, the dual control assembly is provided with a control knob that actuates the thermostatic valve, co-axially arranged with a second control knob that operates the flow rate valve, said two control knobs being provided at the same end of said shower fitting or other water outlet. The first control knob may be mounted on control stem of the thermostatic valve with said second control knob mounted on a (splined) portion of the cartridge/unit being integral with the body thereof. The cartridge/unit may be of a readily available standard form or may be adapted or modified to suit. Where the cartridge/unit is of a standard form the second control knob may be mounted on the splined portion of the cartridge normally utilised for locating a plastics collar of the thermostat control knob.
In another embodiment of the present invention, the operative link or coupling between the thermostatic valve and the flow rate valve is provided by a sleeve surrounding the flow rate valve which sleeve is operatively connected to the thermostatic valve. The thermostatic valve is, preferably, co-axially aligned with the flow rate valve with said sleeve being arranged to turn the body of the thermostatic valve relative to an operating stem of said valve, which stem is held still relative to a mixing chamber of the shower fitting or water outlet. The sleeve (or other operative link or coupling) may or may not be part of the cartridge/unit, or flow rate valve and may or may not be arranged to rotate with the flow rate valve to operate the thermostatic valve.
Preferably, the dual control assembly is provided with a control knob that actuates the thermostatic valve, co-axially arranged with a second control knob that operates the flow rate valve, said two control knobs being provided at the same end of said shower fitting or other water outlet. The first control knob may be mounted on a control stem of the flow rate valve with said second control knob mounted on a (splined) portion of the flow rate valve being integral with the body thereof. The flow rate valve may be of a readily available standard form or may be adapted or modified to suit.
In either of the two above described embodiments the thermostatic valve may be a shuttle valve and/or the flow rate valve may be a disc valve, preferably a C.D. valve.
Further according to the present invention there is provided a shower fitting or other water outlet including a mixing chamber in which can be mounted a thermostatic valve in the form of a cartridge or unit, said fitting or water outlet having a flow rate valve operatively linked or coupled with the thermostatic valve, the thermostatic valve, preferably, being controlled by a control knob mounted coaxially with a control knob for the flow rate valve and said two control knobs, preferably, being mounted at the same end of the fitting or water outlet. Usually, when the shower fitting or water outlet has been installed the thermostatic cartridge will extend forwardly of a vertical wall on which said fitting or outlet is mounted in a generally horizontal plane.
Further according to the present invention there is provided the combination of a thermostatic valve comprising a cartridge or unit insertable into a mixing chamber of, for example, a shower fitting or other water outlet, and means which, in use, forms an operative link or coupling between the thermostatic valve and a flow rate valve of said fitting or other water outlet.
Further according to the present invention, there is provided a dual control assembly comprising a thermostatic valve and a flow rate valve including an operating stem and a body portion, the arrangement being such that the body of the flow rate valve can be rotated relative to said stem to open and close the flow rate valve.
Further according to the present invention there is provided a method of controlling temperature and flow of a liquid medium in, for example, a shower fitting or other fluid outlet, said method comprising setting the temperature of the medium by means of a control knob located at one end of a thermostatic valve in the form of a cartridge or unit and varying the flow rate by means of a second control knob arranged concentrically with the first at the same end of the fitting/fluid outlet.
Still further according to the present invention there is provided a dual control assembly having one or more of the following features:
(a) a thermostatic valve in the form of a cartridge or unit mounted in line with a flow rate disc valve, preferably a CD valve, the body of which may be rotated relative to an operating stem held fixed, in use, relative to a mixing chamber of a shower fitting or other water outlet in which the dual control assembly is mounted;
(b) a thermostatic valve in the form of a cartridge or unit with two concentrically mounted control knobs, the one control knob being for controlling the thermostatic valve and the other control knob being for controlling the flow rate valve preferably operatively coupled to the thermostatic valve, and
(c) a thermostatic valve (in the form of a cartridge) aligned with a flow rate valve in a fluid mixing chamber of a fitting or water outlet, the thermostatic valve and flow rate valve being controlled from the same end of the fitting or outlet by co-axially arranged control knobs.